The Influence Of Using Cervical Headgear With The Fixed Appliances On The Growth And Development Of Maxillary In Patients Had Class Ⅱ Malocclusion With Moderate Or Severe Dental Crowding

OBJECTIVE: The purpose of this retrospective investigation was to evaluate thecervical headgear with the fixed appliances have any effect on the growth anddevelopment of maxillary in adolescent patients, they had Class II malocclusion andmoderate or severe dental crowding.METHODS: Collected160cases which using the cervical headgear with the fixedappliances from October2007to April2012in our hospital, And according to thewhether they were be end of the transitional malocclusion or the early stages of thepermanent malocclusion, skeletal Class II, Class II malocclusion, teeth crowding, thesecond maxillary permanent molars was not eruption or still not reach the occlusal plane,in the growth peak, with good compliance, we condition out of29patients for thisresearch. Including24girls and5boys who average age was11.52years（9-14Y）, thehan nationality. Lateral cephalograms were taken before and after treatment, andanalysis of the difference. The main indicators including NA-PA, S-Ptm, ANS-Ptm,Ptm-6, SNA, SNB, ANB.RESULTS: The relationship between maxilla and mandibular were improved, obtainNormal occlusal, normal overlap&overbite relationship, and the right midline. Correct course28.3months on average. The SNA reduced0.345degrees(P＞0.05),therewere no significant differences,but we can still think that the A point been significantlyinhibited. SNB increased1.045degrees(P＜0.01), means the mandibular had the normalpotential of growth. ANB reduced1.390degrees(P＜0.01), Due to the inhibition ofmaxilla and the growth of mandibular. both of U1-NA and U1-SN degrees, but therewere no any significant differences(P＜0.05). both of L1-NB and L1-MP increase(P＜0.05), and The lip dip was in the normal range. NA-PAreduced3.586degrees(P＜0.01).Relative to the cranial, the position of maxilla was improved. Ptm-6reduced2.059mm(P＜0.01), the distal movement of first permanent molar was effective.CONCLUSION: The cervical headgear with the fixed appliances could inhibit thegrowth and development of maxillary in adolescent patients, the patients had Class IImalocclusion and moderate or severe dental crowding. That is to say the orthopaediceffect is also existing in low traction. But the mandibular was not affected. The using ofthe cervical headgear with the fixed appliances in earlier, was helpful to correct Class IImalocclusion.